Hi. I've notice that most hard drive cleaners simply clean up the basic history of records like past typed urls and temporary internet files and cookies. But they don't necessarily securely erase this data, but merely clean up the computer history automatically within Windows. The data is still on my hard drive and in many other hidden or locked folders. How can I securely erase data on my hard drive for free. Thanks for your help.

For 5 bucks (from memory thats what it cost me) I use Eraser.
Had it now for a good year and it will faithfully overwrite your deleted stuff on your hard drive,to make it unreadable.
Go here http://www.heidi.ie
Cheers Robert
PS Far as I know CrapCleaner, which iI love and use regularly just cleans - the basic info is still there unitl overwritten